Silencer advice/ dimensions

[Chuffmeister]

Lots of questions on this one!

I want to return my Austec 'sports' silencer back to normal. It is sleeved and has no wadding. Sounds great with cats in, but too much with cats out. I'm trying to establish which is the most cost effective route to do this, so I guess the cost of materials and fabrication vs the cost of swapping the silencer for aftermarket will be a consideration.

Firstly, what size diameter perforated pipe do I need for the the silencer and where do I find the wadding? How much wadding will I need?

The silencer looks as if it has been re-welded at the end plate, where the exhausts exit the silencer (see old pic attached). The seam in the centre is apparently factory. How do they do it this way? Are the sleeved pipes literally slotted inside the silencer and held in place by the protruding main pipes once the end plate is re-welded? Or are both ends of the box removed and the pipes spot welded?

Also, has anybody got their standard silencer off at the moment who would be prepared to measure it? The above may need more fabrication so may cost more? I was considering an aftermarket silencer, but need to price up one that will fit. Something like the below would do, but I have no ideal of the dimensions etc of the standard silencer. Space is tight, so I need to get it right!

http://www.ebay.co.uk/itm/Magnaflow-2-25-4x9x14-in...

I can't afford the ACT exhaust unfortunately. But which ever method is cheapest/ best above would do me.

Cheers
Chuffy

Standard Exhaust. Weld bead at end plate where exhausts exit?




Edited to say, I hate iPad predictive text....

Edited by Chuffmeister on Saturday 2nd August 13:34

[Chuffmeister]

SILICONEKID345HP said:

Why do people not take advice from TVR owners who have been down this route .. been there done it and got the Tee shirt

For crying out loud Daz... It came with this exhaust fitted. I can of course ask the previous owner for you!

Edited by Chuffmeister on Saturday 2nd August 16:10

[Chuffmeister]

ClassiChimi said:

There's a really good video somewhere Chuff that demonstrates what to do, if I remember correctly you cut the box from the top and bend a flap up large enough to work with, avoiding your old weld line, remove wadding,cut out the old tubes running through the box with the grinder, cut new tubes to length( sorry don't know the dia) pop in place and a couple of tac welds to hold then really ram as much wadding as you can get back into box, finally bend your flap back and weld. Sounds easy! Where you can get perforated pipes from I have no idea.
The video makes it look like a five quid job if you have a good workshop.

Dunno if any of that helps.

Cheers Alun. I've seen that vid, but wanted to avoid bdising the box. Thought it may have been quicker and easier to remove the end. It looks like it was done this way previously, so I can only assume that the sleeves aren't welded in. It's not a problem going down this route, but it will need plasma cutting. I still need the dimensions of the perf and wadding.

Edited by Chuffmeister on Saturday 2nd August 16:12

[Chuffmeister]

I have thought of swapping, but I have a flexi fitted to mine as it's a 500. The new flexi also facilitates the removal of the y-piece without too much trouble. My concern is that a replacement exhaust won't fit. At the moment, everything marries up perfectly, even the bolt hole at the front! I guess you could always cut the pipes and quickly swap the boxes only???

Edited by Chuffmeister on Saturday 2nd August 23:17

[Chuffmeister]

sapper said:

You can buy perforated pipe and wadding off e-bay. http://www.ebay.co.uk/sch/i.html?_odkw=perforated+... 1m will be plenty
http://www.ebay.co.uk/itm/Exhaust-Silencer-End-Can... buy 2, that should be enough
I did it a few years ago and used 50mm OD perf pipe. The half and half picture shown earlier was my re-work after sh** installed as a sports exhaust. (what's sporty about rusty pipe ill never know)
Slice the top off your silencer box with a 1mm cutting disc and you will be able to DIY or grab a mate with a mig welder.
Its not hard to do and wont take more than a couple of hours.

Edited by sapper on Sunday 3rd August 08:05

Cheers for that, I'll pick those bit up. I'm gonna get 'the man' to do it. Have a quality metal worker/ welder nearby at very competitive rates. Saves me farting around for hours.

[Chuffmeister]

Great visual. I've been toying with the idea of semi-sleeved. Does it get rid of the agricultural farting sound? Also, we're the original perforated pipes welded in or just held in by the larger OD pipe at each end?

Cheers
Chuffy

[Chuffmeister]

sapper said:

Because its perf pipe, therefore not gas tight, you don't need to fully weld it. As in all the way round. Original will be welded or they could move an end up tattling, but you only need to tack weld in place.

Now I understand! Thanks again!

[Chuffmeister]

Thanks!

[Chuffmeister]

Just an update. I removed the exhaust again today whilst the car is on stands (doing the sump). Looking at it in more depth, it certainly seems as if the Austec 'sports' version was done by cutting and re-welding the end of the silencer. I decided to go in by the same route. Basically their were two flared steel sleeves that had simply been pressed onto the exhaust entering the silencer at the other end and then held in place once the end of the silencer had been welded back on. The pics speak for themselves.

I've also done a rough sketch for anybody wanting the dimensions of the silencer and photos on the internal pipes etc. I'm sure so somebody will find it useful..

Cheers
Chuffy

[Chuffmeister]

Perf and glass all in now. Packed in tight. 51mm perf a perfect fit. Off to the welders on Monday!

[Chuffmeister]

QBee said:

Let's hope you are "chuffed" with the resulting sound

That's bad! What is louder... Precats and main cat in with sleeved silencer, or no cats and standard silencer? I want it a quieter, but not silent! I just want to get rid of the agricultural farting sound, but still want it to sound great under load. I was considering using the old sleeves and wrapping them around part of the length of the perforated pipe to make it semi-sleeved. Just not sure on volume, whether semi sleeved will be too loud?

[Chuffmeister]

QBee said:

Get the decibel 10th iPhone app and measure the noise level at 4500 rpm from half a metre above and out from the tail pipes, when you have it all back together.
I will test mine tomorrow. Mine is cats out, standard silencer, which is around or just over 105 dB(A) according to MSV race tracks.
Then we can compare.
I would think cats in, sleeved will be louder.

Can't do it Anthony... No iPhone and exhaust in pieces off car awaiting welder. Perhaps somebody else will have a result with cats in and sleeved?